The present invention relates to disposable medical sponges or wipes which are impermeable to infectious agents, such as the virus that causes Acquired Immune Deficiency Syndrome (AIDS).
Since the beginning of the century, designers of disposable absorbent articles have always been, and still are, confronted with the problem of having liquid migrating laterally on one side of the absorbent article and seeping over the peripheral edges to reach the opposite side of the article. Yet, there is so far no satisfactory solution to this problem.
As will be discussed later, there is a need of having disposable medical sponges or wipes that will not allow the seepage of patient's body fluids and pathogens through the sponges or wipes to infect a health-care worker. It is well documented that body fluids from an infected person do carry with them infectious agents, such as the virus that causes the deadly AIDS. A "leaky" medical sponge or wipe can also expose the patient to possible contamination by an infected health-care worker. A simple impermeable membrane interposed to the medical sponge or wipe will not completely solve the problem. Absorbed body fluids, together with any infectious agents that might be present therein, can still migrate laterally on the absorbent side of the sponge and seep around and over peripheral edges from this absorbent side to the opposite non-absorbent side which is being held by a health-care worker. A desirable medical sponge or wipe must additionally have wet strength, namely, they must not disintegrate when totally soaked in liquids, such as body fluids or a solution of antiseptics.
Disposable absorbent articles, such as diapers, underpads, surgical dressings, medical sponges, wipes, and cosmetic squares, are well known in the prior art. These articles can be broadly divided into two classes: those with a water impermeable sheet and those without a water impermeable sheet.
Articles containing a liquid impermeable sheet have the same general structure. They usually contain an absorbent medium enclosed by a liquid permeable top sheet and a liquid impermeable backsheet. The top sheet is the sheet in direct contact with the skin of the user. Its function is to draw the waste away from the contacting skin into the absorbent medium where the waste is retained. The top sheet reduces the direct contact of the waste with the skin. The water impermeable backsheet prevents the absorbed waste from leaking out of the absorbent article and soiling the surrounding area. The prior art is replete with variations of these general structure. Diapers, sanitary napkins, under pads, are some of the examples.
Another broad class of disposable articles include medical sponges, wipes, gauze, and cosmetic squares. Typically, they contain a layer of porous absorbent material only. There is no separate top sheet, nor is there a layer of material impermeable to water. Consequently, there is not much variation in the overall structure of such a disposable article. Medical sponges or wipes are used to wipe blood or other body fluids from the body of a patient. They are also used to apply pressure or solutions of antiseptic to the body of the patient after, or in preparation for, an injection or a venipuncture procedure.
U.S. Pat. No. 1,843,037 to Mathey discloses a relatively inexpensive sanitary napkin that does not readily leak and stain the clothing. The article contains a separator element such as a thin sheet of lightly waxed crepe cellulose paper. There is an absorbent pad on either side of this separator which extends flush with the marginal walls of the pad. The separator retards fluid flow to the next layer of pad until complete diffusion has ensued in the top pad. Afterward, the separator permits seepage of fluid through it to the bottom pad where the same diffusion action occurs due to the presence of the garment protection. The separator does not completely stop the penetration of fluids, rather it simply retards the seepage of fluids from one pad to the other.
U.S. Pat. No. 4,321,924 to Ahr discloses a bordered disposable absorbent article. The article is for absorbing liquids, such as menstrual discharges. The disposable absorbent article contains an absorbent core encased between a liquid permeable top sheet and a liquid impermeable backsheet. The article is further provided with a thin flexible border which encircles the absorbent core. The border may be formed by extending the back sheet and the topsheet, which is liquid permeable, beyond the absorbent core and affixing the topsheet to the backsheet along two liquid impermeable seams. An inward seam is positioned to the core and an outward seam is positioned in spaced relation to the inward seam, thus forming an enclosed channel which encircles the absorbent core. The enclosed channel is bound by the two liquid impervious seams. To the top of the enclosed channel is the liquid permeable topsheet, and to the bottom of the enclosed channel is the liquid impermeable backsheet. The topsheet and the backsheet are affixed to one another by the inward seam on the inside, and they are affixed to one another at the outer periphery by the outward seam. Hence, the liquid permeable topsheet is flush with the liquid impermeable backsheet at the outward seam. Seepage from top to bottom sheet is not reliably retarded, however.
U.S. Pat. No. 3,779,246 to Mesek and Repke describes a disposable diaper. The disposable article contains an absorbent fibrous pad enclosed by a fibrous facing layer and a water impervious sheet which, in turn, is enclosed by a fibrous outermost layer. The fibrous outermost layer is incorporated to increase the stability and functionality of the diaper. Again, the peripheral edges of all three layers, namely, the fibrous facing layer, the water impervious sheet, and the fibrous outermost layer, are all contiguous and flush to one another.
A U.S. patent issued to Puletti and Decowski under U.S. Pat. No. 4,627,847 describes a hot melt adhesive waste barrier. The invention relates to waste barriers for use in disposable absorbent articles such as diapers, sanitary napkins, bed pads, and the like. The patent describes the creation of a self-adhesive, leakage-resistant, waste barrier on the nonwoven topsheet by coating or depositing a hot melt adhesive to a portion of this topsheet, thus creating a liquid impermeable film. The nonwoven topsheet is in contact with at least one surface of an absorbent core.
U.S. Pat. No. 3,523,536 to Ruffo discloses absorbent fibrous pads which have an absorbent core enveloped in a liquid permeable coverings. The core is composed of predominately short fibers intermixed in a dry state with long fibers to form a heterogeneous mixture in which the long fibers serve to stabilize the short fibers. The liquid permeable coverings, the absorbent core and a layer of synthetic resin film are sealed at their peripheries by means of heat embossing elements.
U.S. Pat. No. 4,338,371 to Dawn and Correale teaches a multilayer absorbent product to absorb fluids. The laminated article is enclosed on the top by a water pervious facing layer for contacting the skin, and on the bottom by a liquid impermeable layer. This liquid impermeable layer, however, is permeable to gas. Immediately under the top water pervious facing layer is the first fibrous wicking layer. Under this wicking layer is the first absorbent mass defined by an inner and an outer layers of wicking material. Under these is another absorbent mass again defined by an inner and an outer layer of a water pervious wicking material. On the bottom is the layer that is impermeable to liquid but is permeable to gas.
A U.S. Pat. No. 3,901,240 issued to Hoey discloses an absorbent article having a top layer of a crushed polymer latex foam either bonded to a non-woven absorbent layer, which is bonded to an absorbent layer, or bonded directly to the absorbent layer. The latter layer is, in turn, bonded either to a flexible, liquid impermeable bottom layer or to a woven or non-woven gauze. The patent describes the procedure for producing such a permeable polymeric liner on absorbent pads.
A patent issued to Hirsch, U.S. Pat. No. 4,477,256, shows a surgical sponge for blunt dissection embodying an X-ray opaque material. The sponge consists of elongated strip of absorbent material such as woven cotton or the like rolled to form a cylindrical structure. The outer layer of the roll is adhesively secured to the roll to prevent unwinding. A radiation opaque material, such as barium sulfate, is contained within the sponge and is intermixed with the adhesive.
U.S. Pat. No. 4,216,774 issued to Graber teaches a reusable, washable incontinent care medical pad. The pad includes a top layer of soft, nonabrasive material, a second inner layer of maximum absorbency and softness material, a third inner layer of structural support material for stitching to the first and second layers. A fourth layer of water impermeable material is then aligned and stitched together with all other layers.
U.S. Pat. No. 3,777,759 issued to Oehmke and Ofstead discloses an enzyme-dispersible bandage. The bandage is a disposable multi-ply pad for contacting the body and absorbing body wastes. The article consists of multiple plys of non-woven, fibrous material of good dry-strength and wet-strength. The wet-strength is being conferred on the article by a binder which is essentially unaffected over periods of several hours by aqueous body waste, but which is rapidly degraded by exposure to aqueous media containing certain enzymes. The whole pad can be readily dispersed and is disposable in domestic waste disposal systems by the addition of enzymes to the disposal receptacle together with the used pad.
Larson in U.S. Pat. No. 3,559,650 teaches a disposable sanitary pad having a disposable absorbent pad on the upper side and a disposable backing of paper or similar material on the under side, with a thin flexible layer liquid-retarding material between the two. All layers have edges flush to one another. Liquid from the pad cannot reach the backing to dissolve it, but liquid reaching the backing from its exposed side will disintegrate it so that the whole article can be disposed of in a toilet. The thin layer of liquid-retarding material cannot remain as a film without the support of the backing material, so that it, too, disintegrates when the backing material disintegrates.
U.S. Pat. No. 3,654,064 to Laumann discloses a waterdisintegratable sheet material. The coated paper is provided in sheet, roll or other physical form and shape which is water-repellent when wetted on either side. The article, however, readily disintegrates when both sides are wetted as when the entire sheet is immersed in water. An extremely thin layer of polyethylene covers a tissue paper which readily disintegrates in water. The polyethylene serves as a hold-out coating for a subsequent water-repellent coating such as a flexible wax layer to prevent the sinking of the wax layer into the tissue paper and rendering the paper water-insoluble and providing it with wet strength properties. A layer of uncoated sheet tissue paper is placed on top of the coated sheet. When wetted on one side, the sheet derives its strength from the bottom layer of paper which is kept dry and strong by the waterrepellent coating. The coating itself has no stretch properties and is very weak. When both top and bottom layers or papers are wetted, as when flushed in a toilet, the entire sheet tears and disintegrates since there remains nothing to support the thin, weak water-insoluble coating.
Although prior art references are replete with references for disposable absorbent articles, none teaches a design to totally prevent the seepage or migration of fluids from one side of the article to the opposite side of the article over the peripheral edges. The prior art references teach that these edges should hold the absorbent and nonabsorbent layers contiguously together in an abutting manner. Hence, liquids absorbed on one side to he article can migrate laterally and seep over the peripheral edges to reach the opposite side of the article. Additionally none teaches a design to prevent penetration of the barrier layer by viral pathogens, the smallest of the infectious agents.
Health-care workers are persons, including students and trainees, whose activities involve direct contact with patients or with human body fluids such as blood, saliva, semen, tears, vaginal secretions, cerebrospinal fluid, amniotic fluid, urine, breast milk, and anal mucus drainage. These health-care workers are at risk of exposure to infectious agents carried by patients on a routine and daily basis. Likewise, patients also run the risk of exposure to infectious agents from infected health-care workers. The term "infectious agents" as used here denotes bacteria, viruses, parasites, and other infectious microorganisms.
The increasing prevalence of AIDS among populations in the world increases the risk that health-care workers will be exposed to blood or other body fluids from patients with AIDS. About 5 to 10 million people from more than 80 countries are infected with this deadly disease. AIDS is caused by human immunodeficiency virus (HIV). To date, AIDS has proven invariably fatal. There is no effective treatment for the disease, nor is there a vaccine to prevent it. On the average, AIDS victims live about two years after the diagnosis. Because the disease has an undetermined period of incubation, a person unknowingly can carry the virus and spread the disease for years. Hence, transmission of disease may occur before the illness is recognizable. The method most frequently used to establish the presence of HIV is the detection of antiviral antibody. Yet, it is known that certain carriers of HIV may harbor the virus for an undetermined time before producing detectable antibodies. A significant proportion of "high risk" groups, such as gay men, illegal drug users, prostitutes, and hemophiliacs, are asymptomatic. This phenomenon suggests that the pool of individuals capable of transmitting the disease is significantly larger than the presently known number of diagnosed AIDS cases. Consequently, health-care workers must consider the blood and other body fluids from all patients as being potentially infective.
AIDS can be transmitted through sexual contact and exposure to infected blood or blood components and perinatally from mother to neonate. The virus, HIV, has been isolated from blood, semen, vaginal secretions, saliva, tears, breast milk, cerebrospinal fluid, amniotic fluid, and urine and is likely to be isolated from other body fluids, secretions, and excretions. So far, epidemiologic evidence has positively implicated blood, semen, vaginal secretions, and possibly breast milk in the transmission of the fatal disease.
A number of health-care workers have been reported to have acquired HIV infection through needlestick, exposure of mucous-membranes or of skin lesions to the blood or other body fluids of HIV-infected patients. The increased risk of a health-care worker to AIDS involves in part the exposure of his or her skin to HIV and the opportunity for HIV to gain access to within the body through cuts, or other skins lesions such as abrasions, scrapes, chapping of the skin or dermatitis. These "defects" on the skin compromise the normal function of the skin as the natural barrier against entry by infectious agents into the body. Viruses, because of their extremely small sizes (usually around 100 namometers in diameter) can enter into the human body through a very minor "defect" of the skin.
In response to the increased risk of exposure of health-care workers to the HIV, the virus causing AIDS, the Centers for Disease Control of the Public Health Service of the United States Department of Health and Human Services has made certain recommendations for the prevention of HIV transmission in health-care settings. See, Supplement, Morbidity and Mortality Weekly Report, Volume 36, No. 2s, Aug. 21, 1987. Among these recommendations is that gloves be worn during the administration of injections to patients or during the drawing of blood from patients. During these medical procedures, it is more than likely that the skin of a health-care worker will get in direct contact with the blood or body fluids of a patient. Wearing examination or surgical gloves provides a barrier to prevent the direct exposure of the skin of the health-care worker to the blood or other body fluids of the patient.
Unfortunately, there are certain drawbacks in wearing gloves while giving injections to patients or while withdrawing blood from patients.
Low cost plastic examination gloves are provided in essentially three sizes. More often than not, they very poorly fit the hands and fingers of a health-care worker. These low cost examination gloves usually have pockets or ridges of excess glove material lying over finger surfaces. The more expensive surgical quality latex gloves usually fit better, but are nevertheless slippery. Moreover, a large number of gloves have process related defects which include small leaks permeable to tiny viruses. Defects in gloves may also include intrinsic weak spots which will develop into leaks while the gloves are being worn and under handling stress. Finger nails, rings, and needle points, among other objects, can unknowingly puncture gloves, creating holes permeable to infectious agents.
Furthermore, the wearing of gloves during injection or venipuncture procedures may compromise the manual dexterity, or "feel," required for the procedure. The loss of manual dexterity during these procedures could lead to an increase in the incidence of needlesticks to the health care worker. Additionally, the decrease of manual dexterity, or the loss of "feel," by a health-care worker could compromise the finesse of touch required in minimizing the pain and discomfort for the patient receiving the injection or venipuncture.
It is a routine procedure to apply an adhesive backed bandage to skin puncture after an injection or a venipuncture procedure. This routine practice poses another problem to the wearer of gloves during a procedure, namely, the invariable stick of adhesive bandages or tape to the gloves. It is virtually impossible to remove an adhesive bandage that has stuck onto a glove without tearing it.
The cost of disposable gloves is not negligible. The time spent in donning and removing them is also costly. All these costs will ultimately contribute to the increase health care cost. The ratio of unit cost of a glove to a sponge or a wipe is approximately 5 to 1.
It is also a routine medical procedure to swab or wipe the skin puncture site with an absorbent sponge, typically of woven cotton, that has been saturated with an aqueous alcohol solution, usually a 70% solution of isopropyl alcohol. This swabbing or wiping is to prevent the entrance of pathogenic or infection agents to the body through these sites. After an injection or venipuncture procedure, an absorbent sponge is used to apply pressure to the skin puncture site to control bleeding.
As discussed above, the Centers for Disease Control has recommended wearing latex or synthetic polymer rubber gloves by health-care workers during the administration of an injection to a patient, or during the withdrawing of blood samples from a patient. The purpose of wearing gloves is to provide a barrier between the fingers and hand of the health-care worker and the patient's body fluids during swabbing, wiping or applying pressure to the skin puncture site. The latex or synthetic polymer rubber materials used in glove manufacture are impermeable to most infectous agents, provided that there are no leaks or other defects in the gloves.
Additionally, compliance is an issue to be considered. Use of gloves by health-care workers may be perceived by the patient as identification with a high risk group having an incurable disease. Additionally, procedural difficulties caused by the wearing of gloves may make health-care workers reluctant to wear them.
The medical sponges or wipes commonly used to swab or wipe the skin punctures have no built in impermeable barrier. Consequently, blood and other body fluids can easily pass through such porous sponges or wipes by capillary action or osmosis. Any infectious agents that might be present in the blood or other body fluids will likewise be carried along and will permeate such sponges or wipes. In view of the fact that sponges or wipes routinely used in wiping body fluids and cleansing skin puncture sites are "leaky," it is sensible for a health-care worker to wear gloves when administering an injection or performing a venipuncture procedure.
Because of their small sizes, infectious agents, such as viruses which may be present in the blood or body fluid, can, by means of capillary action pass through regular sponges or wipes very easily. The isopropyl alcohol solution used in conjunction with sponges or wipes does not necessarily achieve a total kill of all infectious agents that might be present in the blood absorbed into the sponges or wipes. In short, for total protection of both the health-care worker and the patient, a barrier that is impermeable to infectious agents must be interposed between the fingers and hands of the health-care worker and the blood and other body fluids of a patient.
In view of the fact that wearing of gloves poses many problems, it is highly desirable to have medical sponges or wipes with a barrier that is impermeable to infectious agents such as viruses. It is also desirable to have such a barrier that will prevent the seepage of blood or body fluids from the side that is in direct contact with such fluids to the opposite side that is being held by the user's bare fingers. Of course, medical sponges or wipes with a barrier impermeable to infectious agents can be used in conjunction with gloves. The "nonleaky" yet disposable sponges or wipes will offer an additional protection for both the glove-wearing health-care worker and the patient. After all, the gloves being worn could have leaks due to manufacturing imperfections or could have leaks developed during use due to abrasion or puncture.
It is toward such goals that the present invention is directed.